Intro to Proof / Proving Parallel Lines & Transversals

50 Minute Class, Curriculum, Geometry

Learning Goal: Introduce proof structure in a non-math way and then transition towards proving parallel lines & transversal theorems.

Google Slides




  • Common Core
    • HSG.CO.C.9 – Prove theorems about lines and angles. Theorems include: vertical angles are congruent; when a transversal crosses parallel lines, alternate interior angles are congruent and corresponding angles are congruent; points on a perpendicular bisector of a line segment are exactly those equidistant from the segment’s endpoints.
  • TEKS
    • G.4(A) – distinguish between undefined terms, definitions, postulates, conjectures, and theorems
    • G.4(B) – identify and determine the validity of the converse, inverse, and contrapositive of a conditional statement and recognize the connection between a biconditional statement and a true conditional statement with a true converse
    • G.6(A) – verify theorems about angles formed by the intersection of lines and line segments, including vertical angles, and angles formed by parallel lines cut by a transversal and prove equidistance between the endpoints of a segment and points on its perpendicular bisector and apply these relationships to solve problems